Diaphragm valve



Oct. 6, 1953 G E, FRANCK 2,654,559

' DIAPHRAGM VALVE Filed March 8. 1950 Patented Oct. 6, 1953 UNITEDSTATES PATENT OFFICE DIAPHRAGM VALVE George E. Franck, Riverside, Ill.,assignor to The Imperial Brass Manufacturing Company, a corporation oiIllinois Application March 8, 1950, Serial No. 148,360

4 Claims.

ties enabling the diaphragms to resist the chemi cal action of therefrigerante. Others have a tendency to dry out when subjected to heatfor any period of time. Others do not have the necessary physicalcharacteristics. l

It is an object of the invention, therefore, to provide a new andimproved diaphragm valve in which the shortcomings of prior diaphragmvalves above referred to are overcome.

Another object is to provide a diaphragm valve in which the diaphragm iscomposed of material falling in the class of plastics and having boththe necessary chemical as well as physical and thermal properties towithstand the repeated flexings, the temperatures to which the valve issubjected, and above all to be impervious and resistant to the strongchemicals found in refrigeration systems. v

Still another object is to provide a diaphragm valve in which thediaphragm is composed of laminations of plastic materials, eachlamination contributing a certain characteristic to the diaphragm as aWhole, giving the resultant diaphragm all of the necessary chemical,physical and thermal properties.

Other objects and advantages will become apparent from the followingdetailed description taken in connection with the accompanying drawings,in which:

Fig. 1 is an enlarged diametrical section of a diaphragm valve embodyingthe features of my invention.

Fig. 2 is a section taken approximately along the line 2-2 of Fig. 3 andillustrates a modified form of diaphragm unit.

Fig. 3 is a transverse section taken approximately along the line 3-3 ofFig. 2.

While the invention is susceptible of various modifications andalternative constructions, it

is herein shown in a preferred embodiment and one modication. It is notintended, howeven 2 and alternative constructions falling within thespirit and scope of the invention as dened in the appended claims.

The invention is embodied in a diaphragm typel valve of more or lessconventional construction comprising generally a main body member 5, abonnet 6, a diaphragm unit 'I and an actuating means 8. The main bodymember is generally cylindrical with a central axially opening chamber9. Opening to the chamber are two ports or passages I0 and II, eachterminating at the outer end in a radially projecting, externallythreaded nipple I2 for the attachment of a conduit or pipe. One of thepassages, herein II, opens to the -chamber 9 centrally thereof through aboss I3 projecting slightly above the bottom of the chamber to form, aswill presently become apparent, a valve seat. The other passage I0 opensto the chamber also through the bottom I4 thereof but near theperiphery.

Completing the casing of the valve is the bonnet 6 which also isprovided with a chamber I5. The bonnet at its inner end is externallythreaded to cooperate with internal threads formed in the upstandingannular flange-like portion I6 of the main body member. Threaded throughthe outer end of the bonnet B is a valve actuating stem I'I having anactuating handle I8 nonrotatably iixed on the outer end thereof andterminating at its inner end in a socket I9.

The chamber 9 in the main body member is t,

stepped radially outwardly at a point slightly above the top of the bossI3, as viewed in Fig. 1,

so as to form an annular shoulder 20. Adaptedk to be clamped between theshoulder 20 and the inner end of the bonnet 6 is the peripheral edge ofthe diaphragm unit 'l in order that the diaphragm may serve as a valvecooperating with the seat formed by the boss I3 to control flow betweenthe passages I0 and II.

Herein the diaphragm proper is composed of I materials falling in thegeneral class of plastics. In order that the diaphragm may have thenecessary physical and thermal characteristics, such as iiexibility,strength to withstand pressiues to which it is subjected, resistance todeterioration due to temperature change as well as the necessarychemical characteristics, the diaphragm is here given a laminatedconstruction. A first or main lamina 2| is composed of one of theplastics having the desired thermal and physical properties orcharacteristics. made comparatively thick being on the order of M3 andis composed of a material which at that thickness has flexibility andstrength to with' This lamina is stand the pressure to which thediaphragm is subjected. A preferred material is polyethylene. Thismaterial, in addition to possessing the characteristics above noted hasthe advantage that it is relatively inexpensive and thus contributestoward the perfection of a competent yet not expensive diaphragm valve.

It is desirable in diaphragm valves that 'the valve stem be capable oflifting the diaphragm oil its seat as well as to be able to force thesame down against the seat. This requires the valve stem to be securedor attached to the diaphragm and has also presented a problem. Any`fastening arrangement which pierced the `dia.- phragm was, of course,undesirable `because of the reduction in protection and eiectiveness ofthe diaphragm to prevent leakage.. ,Bi-ezine er welding or in some othermanner securing ,an actuating means to a metallic diaphragm has resultedYin a weakening of the diaphragm and a setting -up of'local stresseswhich after ahum:` ber of -exing operations Acaused :breakdown .of thediaphragm. By the construction about fto be described, this problem isalso overcome. Herein there is provided -a 4cap-like Ielement 22 formedexternally with-an annular groove i23 by which it is rotatably receivedinthe socket-:like member .19. Internally the cap -22 is .formed withIan 'axial bore A21| opening through one end of the cap .but not throughthe other. Intermediate -its ends the bore 24 is expanded radi,- ally tohave'an vannular groove 25. The lamina 2'| is cast and, as an incidentto the casting operation, some Yof the Imaterial composing the laminaris aforced into the'bore 24 :and vits groove 25 so that Ian integralpart of vthe :lamina i2| is secured to -the fcap .member f22. =With thematerial composing Ythe lamina k2| .expandedainto the lgroove 25 ythereis little .possibility of .the cap 22 being -pulled oi of fthe'lamina.

The secondlamina 26 is .placed overthat .face of the lamina 2| which isexposed to-the -i'luid flowing through the valve. This :lamina V'isselected -for its chemical stability, particularly iits resistance to-chemicals present in refrigeration systems. The physical -propertiesvofthis lamina are -not of great importancebecause theseprop.- erties are`supplied .by the lamina 2|, lsave vthat the vlamina 26 should `belflexible in thin section. Apreferred material andtheone of .whichlamina 26 herein is composed-is .polytetrauoroethylene The'lamina 26herein has a thickness of only .03". `The lamina 26 is not and need vnotvbe bonded :to the 1lamina 2|, `but `:is 4simply placed over the laminaJ2| since itis held .securely and in luid-tight relationship .around `itsV.periphery by the clamping action between the bonnet 6 and the-shoulder20. To secure .the lamina A:26 lat rits center, it and the lamina 2| aredrilledaxially with the bore running into but not :through the axialprojection of the Alamina 2| extending 'into thecap member 22. A screw2.1 whose threads have a vroot diameter equal to the bore Vin thelaminae 2| and 26 is then turned into the bore with .a washer 28 of thesame material as the lamina 26 `interposed between the `head vof thescrew and the lamina. As `the screw is drawn down, 'it causes the washer28 to form a tight seal with the lamina 26 around the bore into whichthe screw 21 is threaded, thereby preventing 'any of the chemical`reaching the lamina 2|. While it is desirable to keep the chemical4controlled'by the valve away from the lamina'2 I no great harm is done-should there be slight leakage for :the polyethylene .composing `the`lamina =2| is 4 itself highly resistant to chemicals, though admittedlynot possessing the degree of resistance possessed by lamina 26.Furthermore should there be some leakage between the washer and thelamina 26, there would still be no escape of fluid for lamina 2| is acompletely imperforate dienhraem` v The screw ,21 yperforms ,a secondfunction in that, as it is turned into the bore drilled in the ,axialextension or projection of the lamina 2|, it reduces the opening in thecap member 22 and'gthus further reduces the possibility of theprojection being pulled out of the cap member during Yan unsealing orvalve opening operation.

g and v3 there is disclosed a slightly modified form of diaphragm unit.In this form .theldiaphragm still composed of two laminae 2|' lld'composed of the same materials respectively as the laminae 2| and 26.Also still forming a part of the diaphragm unit is a caplike member-29generally similar to thecap meinber 22 save tor the shape of its -recess'30 v`into which a portion ofthe lamina =2|' -is forced-during thecasting operation. This recess 30 :is of uniform size throughout -itslength, having I,n o annular V4restrictions Aor enlargements, `but isformed with longitudinally lextending serrations 3| (see Fig. 3) whichyserve `firmly 'to hold the cap member and the diaphragm-iorminglaminations against relative rotation. Also present is a screw 21 and aWasher 28. 1n Lthis form, however, the screw v21' extends intofthe -capvmember 29 so as to form aneven more positive retention of the capmember onthediaphragm proper. While in this modification thediaphragm-proper, that is, the laminae 2| Aand .26', are'nolongierimperforate, the likelihood of leakage is almost an improbability. Withthe lscrew j2-| threaded into the cap member, the vwasher may be verytightly drawn against the lamina 26' v`thereby eliminating or at leastreducing to -the vanishing point the possibility of leakage at thatFurther, vwith the bore through the laminations having a diameter equalto vthe'root diameter of the threadsof the screw 21', the screw -fonjnsits own threads in the lamina 2|' for example, and thus there is a sealthroughout-the entirvportion of the screw embedded inthe lamina 2|. Theclamping action between the cap member and the screw head andwasherjurther eiects a seal throughout the entire contact area betweenthe lamina 2 and the cap member.

I claim as my invention:

1. A valve comprising, in combination, a main body member having achamber, a boss centrally of the chamber, apairofports insaid'bpdyHlqlll' ber opening tothe chamber, one of the ports opening 'throughsaid boss, a tbonnet vthreaded into said `body member, a valve actuatingstern projecting from said bonnet in axial alignment with said boss andcarrying at 4its inner end a socket-forming member, a metallic ,cap

member engageable with said ,socketfmmber to be rotatable relative`thereto while restrained against axial movement relative thereto ,andhaving an axially opening recess, and a exible diaphragm in overlyingrelation to said boss clamped at its vperiphery between said bonnet 'andsaid body member and rat its center having an axial `pr-ojec-tioncastinF-the recess in said cap member, said diaphragmibeing composed ofa `plurality of laminations of materials falling in the class ofYethylene polymer plastics, one of which laminations provides strength4to vresist the physical forces 'to which the diaphragm is subjected andthe other of which resists the chemical actions to which the diaphragmis subjected.

2. A valve comprising, in combination, a main body member having achamber, a boss centrally of the chamber, a pair of ports in said bodymember opening to the chamber, one of the ports opening through saidboss, a bonnet threaded into said body member, a valve actuating stemprojecting from said bonnet in axial alignment with said boss andcarrying at its inner end a socket-forming member, a metallic cap memberengageable with said socket member to be rotatable relative theretowhile restrained against axial movement relative thereto and having anaxially opening recess, an imperforate iiexible diaphragm in overlyingrelation to said boss clamped at its periphery between said bonnet andsaid body member, said diaphragm being composed of a rst relativelythick lamina having an axial projection cast in the recess in said capmember, and a second relatively thin lamina of a material highlyresistant to chemical acti-on, and a screw extending through said secondlamina and into the axial projection of said rst lamina and terminatingwithin said axial projection, said screw being self-threaded into thelaminae to hold said laminae together and expand said axial projectiontightly within the recess in said cap member.

3. As an element in a valve, a diaphragm unit comprising a rstrelatively thick lamina cornposed of one of the ethylene polymerplastics exible at the thickness of the lamina and having the strengthto withstand certain pressures, a second relatively thin lamina composedof one of the ethylene polymer plastics highly resistant to chemicalaction, a cap-like element having an axial recess opening through oneend only thereof, an axial projection on said iirst lamina cast withinthe recess in said cap-like element,

and a screw self-threaded through said second lamina and into theprojection of said rst lamina to hold the laminae to said cap member.

4. As an element of a valve, a diaphragm unit comprising a cap-likeelement having an axial recess openingonly through one end thereof andthe recess having intermediate its ends an annular groove, a firstlamina composed of polyethylene having an axial projection cast into andiilling the groove and said recess, said first lamina being iiexible andproviding a certain resistance to rupture, a second very thin laminacomposed of polytetrafluoroethylene highly resistant to chemical action,said second lamina being substantially about one fourth as thick as therst lamina, a hole extending through said second lamina and into theaxial projection of said rst lamina and terminating Within saidprojection, a screw self-threaded in said hole to expand said axialprojection tightly within the recess in the cap-like element, and awasher of the same material as said second lamina interposed between thescrew head and said second lamina to form a seal around the opening insaid second lamina through which said screw projects.

GEORGE E. FRANCK.

References Cited in the file of this patentk UNITED STATES PATENTSNumber Name Date 572,580 Spitzenberg D'ec. 8, 1896 1,385,058 Warter July19, 1921 1,470,352 Dubbs Oct. 9, 1923 1,783,281 Cox Dec. 2, 19301,802,136 Carter Apr. 21, 1931 2,323,531 Franck July 6, 1943 2,394,243Joyce Feb. 5, 1946 2,416,061 McAlevy Feb. 18, 1947 2,459,720 PoltorakJan. 18, 1949

